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This has been annoying me since I first tried a PC after using Atari computers since they were a thing. No matter what monitor I use, it will take for ever to s
by Moru 4y ago
This has been annoying me since I first tried a PC after using Atari computers since they were a thing. No matter what monitor I use, it will take for ever to switch input port or just a simple change of resolution. I was used to be able to switch resolution several times per frame, you could make a game with low resolution and color on the upper 3/4 of the screen and have the stats in higher resolution 4 color mode on the lower 1/4 of the screen without any sort of delay in the signal, you just set an interrupt on every scanline and if the monitor was painting the 300'th scanline, you witch mode and suddenly it's doing double resolution for the rest of the frame. Then switch back on the Vertical Blanc Interrupt at the start of the frame paint.
I was quite surprised when the brand new PC needed 2-3 seconds just to switch resolution. And we are still there after 30-odd years? A KVM switch with analog signal was just the same, still long time to switch between signals. I'm using a remote control software to the local computers so I don't have to wait between every switch. With the added bonus that I can copy/paste between the computers without having to think.
- bitwize 4y agoOne of the reasons why you could switch modes mid-frame is because the concept of a "video mode" is fundamentally different on a PC than on an Atari or Amiga. On a PC, ever since the EGA, the adapter can output at different horizontal and vertical scan rates and the monitor can adapt to the requested mode from the video card. That's why switching video modes takes a couple seconds and may involve a "click" or two. Upon mode switch, the monitor must resync to the new signal. On the Atari and Amiga, the horizontal/vertical scan rates are constant; the only thing that changes is how scanout turns pixels in video memory into signals for the CRT.
- M95D 4y agoNo. I have a Sony G520 CRT monitor with a hardware switch. When I flip the switch, the other image appears in less than a second. In the past I had a Samsung (I don't remember the model) that made the switch without even interrupting the electron beam, in mid-frame. First 2 frames were garbage, until it sync'd to the new signal, but it only took a blink of an eye to switch (at 85 Hz). It was also very quick to sync after a mode change. I could see BIOS screens that modern flat displays are to slow to display before they dissapear.
- aceazzameen 4y agoOh man, I miss my Sony G520. It's still the best monitor I owned. I haven't had a monitor that nice since I gave it away a decade ago. It was still in great condition at the time too.
- reaperducer 4y agoOn the Atari and Amiga, the horizontal/vertical scan rates are constant I can't speak to the Atari, but my memory is that this is not true of the Amiga. The Amiga could do this amazing thing where it would display multiple resolutions on a monitor at the same time, divided horizontally. Analog was flexible that way. An Amiga could even display two different resolutions from two different sources on the same monitor at the same time. This was part of my workflow when I used an Amiga to do live TV news graphics around 1990.
- bitwize 4y agoYes, because the scan frequency didn't change -- that's what I'm trying to say (my terminology may have been a bit off). The timings of the horizontal and vertical sweep of the beam were constant; upon mode change the CRTC changed how scanout occurred, doubling the width or height of pixels in lower resolution mode but it didn't change the scan frequency, allowing the mode change to occur while the beam kept moving along. PC monitors were analog too, but with PC monitors from EGA onwards, changing modes meant potentially changing scan frequency, which required the monitor to sync with the signal at the new frequency. Apparently a high-quality Sony monitor could do this instantly but many of us were slumming it with monitors that took a while to sync.
- Moru 4y agoThe Amiga could do a lot more than the Atari with the gfx chip. The Atari had three modes, 320x200, 640x200 and 640x400 so two horizontal and two vertical resolutions. It also can change frequency between 50 and 60 Hz but that wasn't instant, it took a couple of frames to stabilize. This I think you could use to get borderless screens with even higher resolution but I've forgotten exactly how it worked. For the highest resolution you needed a better monitor though so I didn't have much experience with that one. The Atari Falcon also had more resolutions with instant switch but my memory is getting quite fuzzy there :-)
- kalleboo 4y agoIt was really jarring when I got my M1 Pro MacBook and switching resolutions on the internal display was literally instant. No black screen between the switch whatsoever, it was just there. Makes you wonder what else we've been missing out on all this time.
- abhinavk 4y agoIt's because Macs (almost) always output the native resolution of the display. What you are changing is the draw resolution or scaled resolution.
- kalleboo 4y agoThat may technically true, but on the Intel MacBooks, switching resolutions was still a major ordeal with multiple black screens flickering past.
- bombcar 4y agoIirc max’s also always do encrypted hdmi stuff or whatever it is whereas other OS may only turn that on when a movie is playing.
- VLM 4y agoGood news is thruput always increases with computers over time, bad news is latency only increases over time. See, for example, boot up times. Also see how recovering from sleep/hibernation is now slower than 80s computer boot times, so expect a second layer of abstraction to form soon in the market, a faster recovering sleep mode than actual sleep mode.